Dual cell lcd apparatus, control circuit and control method thereof

ABSTRACT

A dual cell LCD apparatus that includes a LCD display panel, a backlight circuit and a dual cell LCD control circuit. The LCD display panel includes a back cell and a front cell. The dual cell LCD control circuit includes a back cell control circuit, a backlight control circuit and a front cell control circuit. The back cell control circuit retrieves a plurality of luminance and color parameters of a display frame data to further generate back cell control parameters to control the back cell layer. The backlight control circuit performs a statistics analysis of the display frame data according to the luminance and color parameters to further generate a plurality of duty parameters to control the backlight circuit. The front cell control circuit performs an intensity compensation on the front cell according to the luminance and color parameters, the duty parameters and the display frame data.

RELATED APPLICATIONS

This application claims priority to China Application Serial Number201910841690.6, filed Sep. 6, 2019, which is herein incorporated byreference.

BACKGROUND Field of Disclosure

The present disclosure relates to a liquid crystal display technology.More particularly, the present disclosure relates to a dual cell liquidcrystal display apparatus, a control circuit and a control methodthereof.

Description of Related Art

Liquid crystal devices are widely used in a variety of displayapplications. One of the principal reasons for the popularity of liquidcrystal displays is their small size and low power consumption. Inrecent years, the liquid crystal devices having dual cells become moreand more popular since an additional layer of liquid crystal cells isbeneficial for lowering the amount of light leakage. However, due to thepresence of the additional layer of liquid crystal cells, the controlmechanism of the liquid crystal devices becomes more complex as wellsuch that both the cost and the area of the liquid crystal devices areincreased.

Accordingly, what is needed is a dual cell liquid crystal displayapparatus, a control circuit and a control method thereof to address theabove issues.

SUMMARY

An aspect of the present disclosure is to provide a dual cell liquidcrystal display (LCD) control circuit that includes a back cell controlcircuit, a backlight control circuit and a front cell control circuit.The back cell control circuit is configured to retrieve a plurality ofluminance and color parameters of a display frame data to furthergenerate back cell control parameters to control a back cell layer of aLCD display panel. The backlight control circuit is configured toperform a statistics analysis of the display frame data according to theluminance and color parameters to further generate a plurality of dutyparameters to control a backlight circuit. The front cell controlcircuit is configured to perform an intensity compensation on a frontcell layer of the LCD display panel according to the luminance and colorparameters, the duty parameters and the display frame data.

Another aspect of the present disclosure is to provide a dual cell LCDcontrol method used in a dual cell LCD control circuit that includes thesteps outlined below. A plurality of luminance and color parameters of adisplay frame data are retrieved by a back cell control circuit tofurther generate back cell control parameters to control a back celllayer of a LCD display panel. A statistics analysis of the display framedata is performed according to the luminance and color parameters by abacklight control circuit to further generate a plurality of dutyparameters to control a backlight circuit. An intensity compensation isperformed on a front cell layer of the LCD display panel according tothe luminance and color parameters, the duty parameters and the displayframe data by a front cell control circuit.

Yet another aspect of the present disclosure is to provide a dual cellLCD apparatus that includes a LCD display panel, a backlight circuit anda dual cell LCD control circuit. The LCD display panel includes a backcell and a front cell. The dual cell LCD control circuit includes a backcell control circuit, a backlight control circuit and a front cellcontrol circuit. The back cell control circuit is configured to retrievea plurality of luminance and color parameters of a display frame data tofurther generate back cell control parameters to control the back celllayer. The backlight control circuit is configured to perform astatistics analysis of the display frame data according to the luminanceand color parameters to further generate a plurality of duty parametersto control the backlight circuit. The front cell control circuit isconfigured to perform an intensity compensation on the front cellaccording to the luminance and color parameters, the duty parameters andthe display frame data.

These and other features, aspects, and advantages of the presentdisclosure will become better understood with reference to the followingdescription and appended claims.

It is to be understood that both the foregoing general description andthe following detailed description are by examples, and are intended toprovide further explanation of the disclosure as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure can be more fully understood by reading the followingdetailed description of the embodiment, with reference made to theaccompanying drawings as follows:

FIG. 1 is a block diagram of a dual cell LCD apparatus in an embodimentof the present invention;

FIG. 2 is a block diagram of the dual cell LCD control circuit in anembodiment of the present invention; and

FIG. 3 is a flow chart of a dual cell LCD control method in anembodiment of the present invention.

DETAILED DESCRIPTION

Reference will now be made in detail to the present embodiments of thedisclosure, examples of which are illustrated in the accompanyingdrawings. Wherever possible, the same reference numbers are used in thedrawings and the description to refer to the same or like parts.

Reference is now made to FIG. 1. FIG. 1 is a block diagram of a dualcell LCD apparatus 1 in an embodiment of the present invention. The dualcell LCD apparatus 1 includes a LCD display panel 100, a backlightcircuit 110 and a dual cell LCD control circuit 120.

The LCD display panel 100 includes a back cell layer 102 and a frontcell layer 104, in which both the back cell layer 102 and the front celllayer 104 include liquid crystal molecules. In an embodiment, the frontcell layer 104 is configured to display a display frame according to adisplay frame data DFD, and the back cell layer 102 is configured tolower the amount of light leakage of the LCD display panel 100.

It is appreciated that the configuration illustrated in FIG. 1 is merelyused to describe the concept of the operation. In practicalimplementation, the display frame data DFD may be transmitted to the LCDdisplay panel 100 through such as, but not limited to a driving circuit(not illustrated).

The backlight circuit 110 is configured to generate a backlight BL toprovide illumination to the LCD display panel 100.

The dual cell LCD control circuit 120 is configured to control the backcell layer 102, the front cell layer 104 and the backlight circuit 110to accomplish a better control of the amount of illumination fordisplaying the display frame.

Reference is now made to FIG. 2 at the same time. FIG. 2 is a blockdiagram of the dual cell LCD control circuit 120 in an embodiment of thepresent invention. The dual cell LCD control circuit 120 includes a backcell control circuit 200, a backlight control circuit 210 and a frontcell control circuit 220.

As illustrated in FIG. 2, the back cell control circuit 200 includes aluminance and color determining circuit 202 and a back cell decisioncircuit 204.

The luminance and color determining circuit 202 is configured to receivethe display frame data DFD and retrieve luminance and color parametersLCP from the display frame data DFD.

In an embodiment, the luminance and color parameters LCP are retrievedin a region-wise manner. More specifically, the display frame data DFDmay be segmented into different parts corresponding to different regionsof the LCD display panel 100 such that a maximum or an average of theluminance and color intensities of each of these regions is retrieved asone of the luminance and color parameters LCP.

The back cell decision circuit 204 is configured to generate back cellcontrol parameters BCP according to the display frame data DFD and theluminance and color parameters LCP to control an aperture ratio of theback cell layer 102 illustrated in FIG. 1. It is appreciated that whenthe luminance and color parameters LCP are retrieved in the region-wisemanner, the back cell control parameters BCP also control the apertureratio of the back cell layer 102 in the region-wise manner.

The backlight control circuit 210 includes a statistics analyzingcircuit 212 and a duty generation circuit 214.

The statistics analyzing circuit 212 is configured to receive theluminance and color parameters LCP from the back cell control circuit200 to perform the statistics analysis on different frame regions of thedisplay frame data DFD to generate a plurality of statistics analysisresults SA.

As a result, the statistics analyzing circuit 212 perform the statisticsanalysis in a region-wise manner, in which the display frame data DFDmay be segmented into different frame regions corresponding to differentregions of the LCD display panel 100 such that a maximum or an averageof the intensities of each of these frame regions is calculated as thestatistics analysis results SA.

In an embodiment, when the luminance and color determining circuit 202retrieves the luminance and color parameters LCP in the region-wisemanner, the statistics analyzing circuit 212 may directly use theregions corresponding to the luminance and color parameters LCP tocalculate the statistics analysis results SA or further groups theseregions into larger regions to calculate the statistics analysis resultsSA.

More specifically, both the luminance and color determining circuit 202and the statistics analyzing circuit 212 require luminance informationof the display frame data DFD. By using the region-wise retrieving andcalculating methods described above, the luminance information havinglower resolution can be obtained and the luminance and color determiningcircuit 202 and the statistics analyzing circuit 212 can share suchinformation to reduce the overall amount of calculation.

The duty generation circuit 214 is configured to generate dutyparameters DP according to the statistics analysis results SA to controla plurality of duties of backlight regions of the backlight circuit 110illustrated in FIG. 1 corresponding to the frame regions of the displayframe data DFD that the statistics analysis results SA corresponds to.

The front cell control circuit 220 includes a dual cell intensitydetermining circuit 222, a pixel intensity determining circuit 224 and acompensation circuit 226.

The dual cell intensity determining circuit 222 is configured to receivethe back cell control parameters BCP from the back cell control circuit200 to determine dual cell intensities DCI according to the back cellcontrol parameters BCP.

The pixel intensity determining circuit 224 is configured to receive theduty parameters DP from the backlight control circuit 210 to determinepixel intensities PI according to the duty parameters DP.

The compensation circuit 226 is configured to receive the dual cellintensities DCI from the dual cell intensity determining circuit 222 andreceive the pixel intensities PI from the pixel intensity determiningcircuit 224. Further, the compensation circuit 226 is configured toreceive the display frame data DFD to determine original pixelintensities according to the display frame data DFD.

Furthermore, the compensation circuit 226 is configured to generate aplurality of pixel compensation parameters CP according to the dual cellintensities DCI, the pixel intensities PI and the original pixelintensities to perform the intensity compensation on the front celllayer 104 illustrated in FIG. 1.

In some approaches, two separate control circuits are required in orderto accomplish both of local dimming of the backlight circuit and thedual cell operation, in which the first control circuit includes acircuit to determine the duties of the backlight circuit and a circuitto perform compensation on the front cell layer according to the dutiesof the backlight circuit, and the second control circuit includes acircuit to determine the operation of the back cell layer and a circuitto perform compensation on the front cell layer according to theoperation of the back cell layer.

The dual cell LCD control circuit 120 of the dual cell LCD apparatus 1in the present invention is able to perform compensation on the frontcell layer 104 simultaneously according to the duties of the backlightcircuit 110 and the operation of the back cell layer 102 by disposing asingle control circuit. The cost and the area of the dual cell LCDcontrol circuit 120 can both be reduced. Further, due to sharing of theluminance information between the back cell control circuit 200 and thebacklight control circuit 210, the overall amount of calculation can bereduce as well.

Reference is now made to FIG. 3. FIG. 3 is a flow chart of a dual cellLCD control method 300 in an embodiment of the present invention. Thedual cell LCD control method 300 can be used in the dual cell LCDcontrol circuit 120 of the dual cell LCD apparatus 1 illustrated in FIG.2. The dual cell LCD control method 300 includes the steps outlinedbelow.

In step 301, the luminance and color parameters LCP of the display framedata DFD are retrieved by the back cell control circuit 200 to furthergenerate the back cell control parameters BCP to control the back celllayer 102 of the LCD display panel 100.

In step 302, the statistics analysis SA of the display frame data DFD isperformed according to the luminance and color parameters LCP by thebacklight control circuit 210 to further generate the duty parameters DPto control the backlight circuit 110.

In step 303, the intensity compensation is performed on the front celllayer 104 of the LCD display panel 100 according to the luminance andcolor parameters LCP, the duty parameters DP and the display frame dataDFD by the front cell control circuit 220.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the structure of the presentdisclosure without departing from the scope or spirit of the disclosure.In view of the foregoing, it is intended that the present disclosurecover modifications and variations of this disclosure provided they fallwithin the scope of the following claims.

1. A dual cell liquid crystal display (LCD) control circuit, comprising:a back cell control circuit configured to retrieve a plurality ofluminance and color parameters of a display frame data to furthergenerate back cell control parameters to control a back cell layer of aLCD display panel; a backlight control circuit configured to perform astatistics analysis of the display frame data according to the luminanceand color parameters to further generate a plurality of duty parametersto control a backlight circuit; and a front cell control circuitconfigured to perform an intensity compensation on a front cell layer ofthe LCD display panel according to the luminance and color parameters,the duty parameters and the display frame data.
 2. The dual cell LCDcontrol circuit of claim 1, wherein the back cell control circuitcomprises: a luminance and color determining circuit configured toreceive the display frame data and retrieve the luminance and colorparameters from the display frame data; and a back cell decision circuitconfigured to generate the back cell control parameters according to thedisplay frame data and the luminance and color parameters to control anaperture ratio of the back cell layer.
 3. The dual cell LCD controlcircuit of claim 2, wherein the backlight control circuit comprises: astatistics analyzing circuit configured to receive the luminance andcolor parameters from the back cell control circuit to perform thestatistics analysis on different frame regions of the display frame datato generate a plurality of statistics analysis results; and a dutygeneration circuit configured to generate the duty parameters accordingto the statistics analysis results to control a plurality of duties ofbacklight regions of the backlight circuit corresponding to the frameregions.
 4. The dual cell LCD control circuit of claim 3, wherein thestatistics analysis is to calculate a maximum or an average ofintensities of the different frame regions of the display frame data. 5.The dual cell LCD control circuit of claim 3, wherein the front cellcontrol circuit comprises: a dual cell intensity determining circuitconfigured to determine dual cell intensities according to the back cellcontrol parameters; a pixel intensity determining circuit configured todetermine pixel intensities according to the duty parameters; and acompensation circuit configured to determine original pixel intensitiesaccording to the display frame data to generate a plurality of pixelcompensation parameters according to the dual cell intensities, thepixel intensities and the original pixel intensities to perform theintensity compensation on the front cell layer.
 6. A dual cell LCDcontrol method used in a dual cell LCD control circuit, comprising:retrieving a plurality of luminance and color parameters of a displayframe data by a back cell control circuit to further generate back cellcontrol parameters to control a back cell layer of a LCD display panel;performing a statistics analysis of the display frame data according tothe luminance and color parameters by a backlight control circuit tofurther generate a plurality of duty parameters to control a backlightcircuit; and performing an intensity compensation on a front cell layerof the LCD display panel according to the luminance and colorparameters, the duty parameters and the display frame data by a frontcell control circuit.
 7. The dual cell LCD control method of claim 6,further comprising: receiving the display frame data and retrieving theluminance and color parameters from the display frame data by aluminance and color determining circuit of the back cell controlcircuit; and generating the back cell control parameters according tothe display frame data and the luminance and color parameters to controlan aperture ratio of the back cell layer by a back cell decision circuitof the back cell control circuit.
 8. The dual cell LCD control method ofclaim 7, further comprising: receiving the luminance and colorparameters from the back cell control circuit by a statistics analyzingcircuit of the backlight control circuit to perform the statisticsanalysis on different frame regions of the display frame data togenerate a plurality of statistics analysis results; and generating theduty parameters according to the statistics analysis results by a dutygeneration circuit of the backlight control circuit to control aplurality of duties of backlight regions of the backlight circuitcorresponding to the frame regions.
 9. The dual cell LCD control methodof claim 8, further comprising: performing the statistics analysis bycalculating a maximum or an average of intensities of the differentframe regions of the display frame data.
 10. The dual cell LCD controlmethod of claim 8, further comprising: determining dual cell intensitiesaccording to the back cell control parameters by a dual cell intensitydetermining circuit of the front cell control circuit; determining pixelintensities according to the duty parameters by a pixel intensitydetermining circuit of the front cell control circuit; and determiningoriginal pixel intensities according to the display frame data togenerate a plurality of pixel compensation parameters according to thedual cell intensities, the pixel intensities and the original pixelintensities by a compensation circuit of the front cell control circuitto perform the intensity compensation on the front cell layer.
 11. Adual cell liquid crystal display (LCD) apparatus, comprising: a LCDdisplay panel comprising a back cell layer and a front cell layer; abacklight circuit; and a dual cell LCD control circuit comprising: aback cell control circuit configured to retrieve a plurality ofluminance and color parameters of a display frame data to furthergenerate back cell control parameters to control the back cell layer; abacklight control circuit configured to perform a statistics analysis ofthe display frame data according to the luminance and color parametersto further generate a plurality of duty parameters to control thebacklight circuit; and a front cell control circuit configured toperform an intensity compensation on the front cell layer according tothe luminance and color parameters, the duty parameters and the displayframe data.
 12. The dual cell LCD apparatus of claim 11, wherein theback cell control circuit comprises: a luminance and color determiningcircuit configured to receive the display frame data and retrieve theluminance and color parameters from the display frame data; and a backcell decision circuit configured to generate the back cell controlparameters according to the display frame data and the luminance andcolor parameters to control an aperture ratio of the back cell layer.13. The dual cell LCD apparatus of claim 12, wherein the backlightcontrol circuit comprises: a statistics analyzing circuit configured toreceive the luminance and color parameters from the back cell controlcircuit to perform the statistics analysis on different frame regions ofthe display frame data to generate a plurality of statistics analysisresults; and a duty generation circuit configured to generate the dutyparameters according to the statistics analysis results to control aplurality of duties of backlight regions of the backlight circuitcorresponding to the frame regions.
 14. The dual cell LCD apparatus ofclaim 13, wherein the statistics analysis is to calculate a maximum oran average of intensities of the different frame regions of the displayframe data.
 15. The dual cell LCD apparatus of claim 13, wherein thefront cell control circuit comprises: a dual cell intensity determiningcircuit configured to determine dual cell intensities according to theback cell control parameters; a pixel intensity determining circuitconfigured to determine pixel intensities according to the dutyparameters; and a compensation circuit configured to determine originalpixel intensities according to the display frame data to generate aplurality of pixel compensation parameters according to the dual cellintensities, the pixel intensities and the original pixel intensities toperform the intensity compensation on the front cell layer.